"No long-term effect," Detroit coach Mike Babcock said Monday.
Conroy received a double-minor penalty for high-sticking when he lifted his stick and hit Holmstrom's eye.
Babcock said defenceman Brett Lebda is day-to-day with a concussion and ankle injury.
Lebda hasn't played since being punched by Daymond Langkow in Game 5 on Saturday. Lebda was called for a tripping penalty and was punched by Langkow while both were close to the ice.